51 i Total Hydrocarbon Analyzer

Measure total hydrocarbons in emissions from a source using the Thermo Scientific™ Model 51i Total Hydrocarbon Analyzer. The Model 51i utilizes Flame Ionization Detector (FID) technology to provide a wide linear range and sensitive detection of organic compounds. Available in both high-temperature and low-temperature versions.

The Model 51i uses a flame ionization detector, or FID, to measure organic gases and vapors. Flame ionization is a well-known and highly efficient technology used in laboratories and industry for many years.

Key Features:

  • Adjustable ranges
  • Real-time correction of THC readings
  • Temperature-controlled detector oven and sampling system
  • Reporting of alarm conditions

iSeries Advantage:

  • Ethernet connectivity for efficient remote access
  • Enhanced user interface with one-button programming and large display screen
  • Flash memory for increased data storage and user-downloadable software
  • Enhanced electronic design for optimized product commonality
  • Improved layout for easier accessibility to components



Detection Limits0.050 ppm (10 sec. averaging time)
Flow Rate0.75 to 1.5 L/min.
Inputs16 Digital Inputs (Standard), 8 0 to 10 VDC Analog
Linearity±2% of span (at concentrations of 10 to 150% of span)
Response Time15 sec. (1 sec. average time)
Span Drift<2% of range or 0.20 ppm (24 hr.)
Temperature (English) Operating59°F to 95°F
Temperature (Metric) Operating15°C to 35°C
Zero Noise0.025 ppmc RMS
Certifications/ComplianceETL, CSA, UL, CE, UKCA
Depth (English)23 in.
Depth (Metric)584 mm
DescriptionHigh Temperature
Height (English)8.62 in.
Measurement RangePreset Ranges: 0 to 1, 10, 100, 1,000, 5000, and 10000ppmc; Custom Ranges: 0 to 1 to 10000ppmc
Mounting OptionsBench mounting (standard); Ears and handles, EIA;
OutputsSelectable Voltage, RS232/RS485, TCP/IP, 10 Status Relays, Power Fail Indication; 0 to 20 or 4 to 20mA Isolated Current Output (optional)
Precision2.0% of reading or 0.1 ppm (whichever is larger)
Weight (English)50 lb.
Weight (Metric)22.7 kg
Width (English)16.75 in.
Width (Metric)425 mm
Zero Drift<0.50ppm/day
Unit SizeEach